ok let me start off with the basics. the 4.7L has aluminum heads so youll have to buy anti seze and apply it very lightly to the plug being careful not to get it on the electrod this could cause a missfire. then i would get champion plat or iridum plugs. then buy new boots for your coils and make sure to put dialectiric greese inside of the new boots just enough to coat the inside of them. if you still have mpg problems i would start looking at replacing the cat and o2 senors since a bad cat can ruin them and could even come apart clogging your muffler. just a few ideas. dont go cheap 100 to 500 is still cheaper than an engine, espcially a 4.7L

 

yes you can reach them from the top, and of course you need to torque them down, i just dont have the specs on hand, i have never used anti-sieze on spark plugs but if you want to go ahead, the boots of the coils dont need to be replaced unless you want to, or they are cracking/dry rotting (i have never replaced mine)

 

ALWAYSs use antiseize on modern plugs. The metals are too soft for cost cutting needs and run to hot for EPA reasons.

An ounce of prevention is worth a pound of cure. And it costs 99 cents. May save a $500 repair bill.

IndyDurango

 

thanks guys, i think i got all the info i'll need now lol. I can probaly found the torque spec. in my chilton manual. well actually wait, did the 5.2's and 5.9's also have alumini heads to?

 

indy, believe it or not the only time i have ever had trouble getting plugs out even w/o anti-sieze is the factory plugs (probably installed by machines)

 

The 3.9L, 5.2L and 5.9L have iron heads.

The 4.7L have aluminum.


Here is your torque: 41 N·m (30 ft. lbs.) for iron heads.


I see what your saying but if you use a anti-seize you need to use one that is for electrical (spark plug anti-seize). For me I never use it because I don't over torque them down and I replace them once a year anyway so they never have any time to rust not to mention....IMHO.... I don't think you get a very good connection with a anti-seize in between the connections, but again that's my opinion. Now on a spark plug that lasts a long time I might think about it however I would assume that after 60k-100k miles it would be burned off anyway!

 

thanks, im asuming you ment to say alumi for the torque specs correct? one more question, 4.7 wise, what part of the engine is the most restrictive? heads, intake, cams?

 

you always replace boots because of the possiblity of carbon tracking. if you replace your plugs and not your boots and have a carbon track it will transfer to the new plug and last time i check platnium plug arent cheep never use copper core in a coil on plug system

 

WRONG

the trucks came with copper core plugs from the factory, your best bet is to stick with copper core plugs and NOT change the type

 

Here is the specs with aluminum: 4.7L V–8 Engine: Tighten spark plugs to 27
N·m (20 ft. lbs.) torque.


As for restrictive, Cam's are not restrictive as they only operate the valves which in turn are the heads. The most restrictive part would be the heads......IMHO